Vesalius was born in Brussels on 13 December 1514, to a family of physicians from Wesel (the derivation of Vesalius) in Germany. His father was the royal pharmacist to Charles V of Germany, and from an early age Vesalius showed an inclination to follow in the family tradition, by dissecting dead birds and mice. He was educated at the University of Louvain and then studied medicine in Paris. After a period as a military surgeon, he moved to Padua, Italy, where he gained his medical degree in 1537, and was then appointed lecturer in surgery and anatomy. At Padua he published his famous book De humani corporis fabrica/On the Structure of the Human Body (1543), which met with vigorous opposition and led to bitter controversy. In a fit of despondency, he gave up anatomy and resigned his chair at Padua. He became court physician to Charles V and later to his son Philip II of Spain. On his way back from a pilgrimage to Jerusalem, on 15 October 1564, he died in a shipwreck off the Greek island of Zanté (Zakynthos).

Vesalius was taught anatomy in the Galenist tradition. Galen had never dissected a human body - all his accounts of the human anatomy were based on his research of the Barbary ape - although he was regarded as infallible and was venerated until the Renaissance; Vesalius was therefore taught principles of anatomy that had not been questioned for 1,300 years.

The artists of Vesalius's time encouraged the study of anatomy because they wanted accurate representations of the human body. The greatest of these were Leonardo da Vinci, Albrecht Dürer (1471-1528), and Michelangelo (1475-1564). Leonardo, who made more than 750 anatomical drawings, paved the way for Vesalius. Vesalius became dissatisfied with the instruction he had received and resolved to make his own observations, which disagreed with Galen's. For instance, he disproved that men had one rib fewer than women - a belief that had been widely held until then. He also believed, contrary to Aristotle's theory of the heart being the centre of the mind and emotion, that the brain and the nervous system are the centre.

Between 1539 and 1542 Vesalius prepared his masterpiece, a book that employed talented artists to provide the illustrations. The finished work, published in 1543 in Basel, is one of the great books of the 16th century. The quality of anatomical depiction introduced a new standard into all illustrated works and especially into medical books. The text, divided into seven sections, is of great importance in expressing the need to introduce scientific method into the study of anatomy. The De humani corporis fabrica did for anatomy what Copernicus's book did for astronomy (they were both published in the same year). Vesalius upset the authority of Galen and his book, the first real textbook of anatomy, marks the beginning of biology as a science.